I agree - the transitional programme can be misread as economist, but understood properly, and placed in its proper context (obviously we should adapt the demands to the present situation - e.g. in Croatia the transitional political demands might include reforming the judiciary etc. etc.) I think it is a powerful tool for winning over reformist workers, and those subordinated to some reformist or revisionist bureaucracy.
And Martov was, for all intents and purposes, a member of the centre of the Menshevik Party, with open defencists and social-tsarists like Plekhanov being the extreme right, and "revolutionary" defencists like Chkheidze being the "respectable" right. Martov's group would be the centre, whereas certain elements of the Mezhrayonka (Ezhov, Uritsky and others) and Larin's Menshevik-Internationalist groups would be the left.